Norwegian 4x4 workout
Interval Training Timer
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
A private interval timer for the Norwegian 4×4 protocol — live heart-rate zones on iPhone and Apple Watch, plus workout history and VO₂max trends.
Norwegian 4x4 is a focused interval training timer for the proven Norwegian 4x4 protocol — four 4-minute high-intensity intervals with 3-minute active recovery periods.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Your Norwegian 4×4 workouts now build a picture of your fitness over time.
WORKOUT HISTORY & DETAIL
Every workout is saved with full heart-rate detail. Tap any session to see your heart-rate curve with each phase shaded, a per-interval breakdown, and your time in the target zone.
FITNESS TRENDS
A new trends dashboard shows where you're heading — your heart-rate recovery after each interval and your average interval heart rate, each with a sparkline and a week-over-week trend — plus your weekly workout count and current streak.
POST-WORKOUT SUMMARY
See your duration, peak heart rate, and average heart-rate recovery the moment you finish.
MORE RELIABLE APPLE WATCH SYNC
Live heart rate stays current on your iPhone even with your wrist down, and starting a workout on one device keeps the other in sync.
YOUR DATA, YOUR CONTROL
All history is stored privately on your device. Delete any single workout, or clear your whole history, at any time.
The developer, Alice Winthrop, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Alice Winthrop
- Size
- 34.3 MB
- Category
- Health & Fitness
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later. - Apple Watch
Requires watchOS 10.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Unlock Norwegian 4x4 $4.99
- Copyright
- © Alice Winthrop 2026
